package com.kuang.forkjoin;

import java.util.concurrent.ExecutionException;
import java.util.concurrent.ForkJoinPool;
import java.util.concurrent.ForkJoinTask;
import java.util.stream.LongStream;

public class Test{
public static void main(String[] args) throws ExecutionException,
        InterruptedException {
 //test1(); // 12224
 //test2(); // 10038
 test3(); // 153
        }
// 普通程序员
public static void test1(){
        Long sum = 0L;
        long start = System.currentTimeMillis();
        for (Long i = 1L; i <= 10_0000_0000; i++) {
        sum += i;
        }
        long end = System.currentTimeMillis();
        System.out.println("sum="+sum+" 时间："+(end-start));
        }
// 会使用ForkJoin
public static void test2() throws ExecutionException, InterruptedException {
        long start = System.currentTimeMillis();
        ForkJoinPool forkJoinPool = new ForkJoinPool();
        ForkJoinTask<Long> task = new ForkJoinDemo(0L, 10_0000_0000L);
        ForkJoinTask<Long> submit = forkJoinPool.submit(task);// 提交任务
        Long sum = submit.get();
        long end = System.currentTimeMillis();
        System.out.println("sum="+sum+" 时间："+(end-start));
        }


public static void test3(){
        long start = System.currentTimeMillis();
// Stream并行流 () (]
        long sum = LongStream.rangeClosed(0L,
        10_0000_0000L).parallel().reduce(0, Long::sum);
        long end = System.currentTimeMillis();//15、异步回调
       // Future 设计的初衷： 对将来的某个事件的结果进行建模
        //.//
        System.out.println("sum="+sum+"时间："+(end-start));
        }
}
